Pyrrolidines

Pyrrolidines

Levetiracetam, a pyrrolidine derivative, is a newer antiseizure drug that’s chemically unrelated to previously available antiepilep-tic drugs. It’s used as adjunctive therapy to treat certain types of partial and myoclonic seizures.

Pharmacokinetics

Levetiracetam is administered orally or I.V. Oral administration re-sults in rapid and full absorption with a 100% bioavailability. Peak concentrations occur in about 1 hour. Levetiracetam isn’t exten-sively metabolized; any metabolites that are produced aren’t ac-tive. The major metabolic pathway is enzymatic hydrolysis, and metabolism doesn’t depend on any hepatic cytochrome P450 isoenzymes. Levetiracetam is eliminated by renal excretion. The half-life is about 8 hours and is unaffected by dose, route of ad-ministration, or repeated administration.

Pharmacodynamics

The precise mechanism of action isn’t known. The drug’s antiepileptic effect doesn’t appear to involve known mechanisms relating to inhibitory and excitatory neurotransmission.

Pharmacotherapeutics

Levetiracetam has several indications for us, including:

·                 adjunctive therapy for epilepsy in adults and children older than age 4

·                 adjunctive treatment for myoclonic seizures in adults and chil-dren older than age 12

·                 adjunctive treatment for primary generalized tonic-clonic seizures in adults and children older than age 6.

Drug interactions

Levetiracetam has no known major drug interactions. (See Ad-verse reactions to levetiracetam.)